This slow roasted cod is the perfect centerpiece for any dinner party or holiday gathering. The fish is perfectly cooked, the pesto adds great texture, and the whole dish comes together in about 30 minutes.

Fish main courses can be a bit of a risk for a dinner party, it can also be a genius choice. For starters, there are plenty of potential guests who don’t eat meat or poultry, but fish and seafood are part of their diet (a.k.a. pescatarian). Fish is also a great healthy option so guests don’t feel weighed down after a heavy meal. If you purchase fish according to the Monterey Bay Seafood Watch’s guide, serving fish can be a good choice for the planet as well. And last but not least, sometimes the event requires it, like in the Feast of the Seven Fishes around the holidays.
And last, but not least: slow roasted cod doesn’t actually take a lot of time. Slow roasting cod is a little bit of a misnomer. The process takes about half an hour, which is slow… for fish. This recipe is very forgiving and can be altered and adapted to your preferences.
At first glance, this recipe seems to use A LOT of olive oil. And well, it kinda does. However, it is important for the fish to be well coated so it cooks gently and absorbs the flavors of the garlic and herbs. A lot of oil is left in the pan – a few tablespoons are added to the pesto and the rest can be discarded or served for dipping bread in. I do not recommend saving the oil for later use.
My favorite thing about a pesto is that it can be completely customized to suit your tastes. I always seem to have parsley, walnuts, and garlic around… so guess what goes into my pestos? A few tablespoons of the warm olive oil infuse a lot of flavor into a simple list of ingredients.
Looking for a side dish to serve with this easy peasy roasted cod main dish? Try Roasted Delicata Squash with Herb Pesto — you can even make the same pesto for both dishes. For some greenery, try these Green Beans with Mushrooms and Shallots or a Lentil Salad with Marinated Radishes.

Slow Roasted Cod with Pesto
What You’ll Need
- 1 lb cod fillet
- ⅓ cup olive oil
- 3 cloves garlic peeled
- 3-4 sprigs of thyme
- 1 cup parsley loosely packed
- ¼ cup kalamata olives
- ¼ cup walnut pieces
- Salt and pepper to taste
What to Do
- Preheat the oven to 300°. Place the fish into a baking dish, cutting the fillet in half if needed. Season with salt and pepper; then, pour the olive oil over the fish, ensuring it is well coated. Add 2 of the garlic cloves and thyme to the baking dish.
- Roast for 25-30 minutes, or until the fish is cooked through and flakes easily. Discard the thyme and garlic cloves.
- While the fish is roasting, finely chop the herbs, olives, walnuts, and remaining garlic clove together. (Note: you can use a food processor for this, but I like the texture of hand chopping for this recipe!) Set aside in a small bowl.
- Add 1-2 tablespoons of the warm olive oil to the finely chopped herb, olive, walnut, and garlic, until it resembles a pesto sauce. Season with salt and pepper to taste.
This recipe sounds delicious. I am loving the addition of walnuts. Trying it for sure. Thanks for sharing.
What a great idea to serve fish for a dinner party! You’re right it probably fits into most people’s diets!
Love having pesto on hand for a quick meal. A little on chicken or a little on the fish.. and you have a wonderful meal. I love cod with pesto – so much flavor.
This looks delicious and I love that it takes only 30 minutes. And it’s another thing to slather pesto on! 🙂
Looks beautiful and tasty! Your pesto sounds awesome.